Hormonal Contraceptive Fights Hot Flashes

A single shot of the injectable contraceptive Depo-Provera may be better at combating hot flashes than the antidepressant Effexor, a new study shows.

Previous studies have shown that both Effexor and progestins, like Depo-Provera, can help alleviate hot flashes, says researcher Charles Loprinzi, MD, a cancer specialist at the Mayo Clinic in Rochester, Minn.

The researchers decided to pit the two treatments against each other. Nearly 100 women who suffered from severe hot flashes received either a single injection of Depo-Provera or daily Effexor tablets.

To qualify for the study, "women had to have hot flashes at least two times a day on average for at least a month," Loprinzi says. Nearly all (90 percent) had hot flashes four or more times a day. About one-third of the women had hot flashes at least 10 times a day.

By six weeks after the start of the study, about 60 percent of the women on Effexor were having fewer hot flashes. But 80 percent of women who got Depo-Provera reported relief, he says.

The study was presented at the annual meeting of the American Society for Clinical Oncology.

"Another way to put it is that if you look at these women six weeks later, only 1 percent of women on Effexor had no flashes, compared with 24 percent of those who used Depo-Provera," he tells WebMD.

After six months, Depo-Provera still had the edge over Effexor, Loprinzi says. "Almost three times as many patients in the [Depo-Provera] group still reported a 90 percent reduction in hot flashes as compared with patients receiving daily oral [Effexor]," he says.

Since about two-thirds of the women in the study had a history of breast cancer, making them more prone to hot flashes, these findings should benefit a very broad group of women, Loprinzi says.

No Major Side Effects

There were no major side effects among women in the study.

Women who received Depo-Provera reported less trouble sleeping, less constipation, and less sweating than those on Effexor. Women on Effexor, on the other hand, experienced less stress and tension — as would be expected with an antidepressant.

Loprinzi says large clinical trials linking menopausal hormone therapy to an increased risk for cancer have caused concern about the use of estrogen therapy, given with or without a progestin.

The FDA also requires Depo-Provera to carry a "black box" warning stating that prolonged use of the drug may result in the loss of bone density. Loss of bone density increases the risk of osteoporosis, which carries a risk for fractures.

Loprinzi points out that the women in the study received just one injection, which offered protection for months on end. "The risk from a single injection is small, so this is a reasonable option to consider," he says.

If hot flashes start to return, women and their doctors will have to decide whether a repeat shot is a good idea, he says.

Depo-Provera is made by Pfizer, a WebMD sponsor.

Other Researchers Divided

Other experts disagreed about whether they would use a progestin to treat hot flashes.

Leilani Morales, MD, of the University Hospital Gasthuisberg in Leuven, Belgium, says that even if Depo-Provera is slightly more effective, she's still wary of a possible breast cancer risk. "I'd opt for a nonhormonal medication," she tells WebMD.

But William Gradishar, MD, a breast cancer specialist at Northwestern University in Chicago, says that "while it's generally good to avoid hormones, we have to keep in mind that progesterones are actually used to treat advanced breast cancer."

The big question, he tells WebMD, is whether women would choose an injection — even if it's just once — over an oral medication. "In my experience, patients prefer a pill," he says. "But if they suffer terrible hot flashes, a shot even once a month may not seem so terrible."

Also, studies have shown that some antidepressants used to treat hot flashes may decrease the effectiveness of the drug tamoxifen.

One way or another, the new information "is worth sharing with the individual patient as we discuss the risks and benefits of each treatment," Gradishar says.

At the meeting, another study of 132 women showed that the herbal remedy black cohosh does not alleviate hot flashes. Used extensively in Europe to treat hot flashes, black cohosh is derived from a plant that's a member of the buttercup family.

"There was no improvement of symptoms when women took black cohosh compared with placebo," says surgeon Barbara Pockaj, MD, of the Mayo Clinic in Scottsdale, Ariz.

As many as three out of four women in the U.S. experience hot flashes during menopause. To prevent hot flashes, avoid these triggers: